The hematological complications of alcoholism

Abstract

Alcohol has numerous adverse effects on the various types of blood cells and their functions. For example, heavy alcohol consumption can cause generalized suppression of blood cell production and the production of structurally abnormal blood cell precursors that cannot mature into functional cells. Alcoholics frequently have defective red blood cells that are destroyed prematurely, possibly resulting in anemia. Alcohol also interferes with the production and function of white blood cells, especially those that defend the body against invading bacteria. Consequently, alcoholics frequently suffer from bacterial infections. Finally, alcohol adversely affects the platelets and other components of the blood-clotting system. Heavy alcohol consumption thus may increase the drinker's risk of suffering a stroke.

Blood cell development. All types of circulating blood cells develop from a pluripotent stem cell. Under the influence of certain proteins (i.e., growth factors), this stem cell multiplies and differentiates into increasingly committed precursor cells. Through several intermediate stages, these precursors differentiate further and develop into the mature cells circulating in the blood or residing in the tissues.

Figure 1

Causes of anemia in alcoholics. Alcohol, as well as alcohol-induced cirrhosis, leads to decreased red blood cell (RBC) production. Hypersplenism, a condition characterized by an enlarged spleen and deficiency of one or more blood cell types, can induce premature RBC destruction. Blood loss occurs primarily in the gastrointestinal tract (e.g., at the sites of peptic ulcers) and is increased in patients with reduced platelet numbers. Folic acid deficiency impairs RBC production and results from decreased ingestion, decreased absorption, and abnormal metabolism of folic acid. SOURCE: Adapted with permission from Cornwell, G.G., III. Hematologic Complications of Alcohol. Unit 3. Developed by the Project Cork Institute at Dartmouth Medical School. Timonium, MD: Milner-Fenwick, 1981.

Figure 2

Alcohol-induced structural abnormalities in red blood cell (RBC) structure. (A) Normal RBC’s have a characteristic disclike shape; the cell in the center is a neutrophil. (B) Stomatocytes have a defect in their membranes that causes them to assume a mouth-, or stoma-, like shape when viewed under a microscope. (C) Spur cells are characterized by spikelike protrusions that result from the assimilation of excess cholesterol into the cell’s membrane. SOURCES: Images A and B are used with permission from the American Society of Hemotology Slide Bank. Image C is used with permission from Cornwell, G.G., III. Hematologic Complications of Alcohol. Unit 3. Developed by the Project Cork Institute at Dartmouth Medical School. Timinonium, MD: Milner-Fenwick, 1981.